import java.util.Scanner;
public class demo2 {
    public static void main(String[]args){
        System.out.println("请输入分数");
        Scanner input =new Scanner(System.in);
        double score =input.nextDouble();
        if(score>100||score<0){
            System.out.println("成绩输入有误，请重新输入");
        }
        else if(score<=59&score>=0){
            System.out.println("C等级");
        }
        else if(score<=80&score>=60){
            System.out.println("B等级");
        }
        else if(score<=100&score>=81){
            System.out.println("A等级");
        }
    }
}
